Apparatus for manufacturing display device and method for manufacturing display device

ABSTRACT

An apparatus configured to manufacture a display device and a method of manufacturing a display device include a stage configured to place a process target object on an upper surface thereof; a bending head in contact with the process target object to bend the process target object; a distance measurement sensor installed above the stage to be movable in a horizontal direction; and a cylinder configured to adjust a vertical position of the bending head.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Korean Patent Application No.10-2020-0056995 filed on May 13, 2020 in the Korean IntellectualProperty Office, and all the benefits accruing therefrom under 35 U.S.C.119, the contents of which in its entirety are herein incorporated byreference.

BACKGROUND Field

The inventive concepts relate to an apparatus configured to manufacturea display device and a method of manufacturing a display device.

Discussion of the Background

The importance of display devices has steadily increased with thedevelopment of multimedia technology. Accordingly, various types ofdisplay devices such as an organic light emitting display (OLED), aliquid crystal display (LCD) and the like have been used.

Recently, mobility-based electronic devices are widely used. Mobileelectronic devices may include compact electronic devices such as mobilephones as well as table personal computers (PCs).

Such mobile electronic devices are equipped with a display device forproviding a user with visual information such as an image and a video tosupport various functions. Recently, with the miniaturization of theother parts for driving a display device, the display device is becomingone of the largest parts constituting an electronic device and developedto be bent at a certain angle from a flat state.

The above information disclosed in this Background section is only forunderstanding of the background of the inventive concepts, and,therefore, it may contain information that does not constitute priorart.

SUMMARY

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

Aspects of the inventive concepts provide an apparatus to manufacture adisplay device, which is capable of bending a process target objectstably and accurately.

Aspects of the inventive concepts also provide a method of manufacturinga display device, which is capable of bending a process target objectstably and accurately.

Additional features of the inventive concepts will be set forth in thedescription which follows, and in part will be apparent from thedescription, or may be learned by practice of the inventive concepts.

An embodiment of an apparatus to manufacture a display device, includesa stage configured to place a process target object on an upper surfacethereof; a bending head in contact with the process target object tobend the process target object; a distance measurement sensor installedabove the stage to be movable in a horizontal direction; and a cylinderconfigured to adjust a vertical position of the bending head.

An embodiment of a method to manufacture a display device, includestuning positions of a stage and a bending head; placing a target objecton the stage; and bending the target object while the bending head is incontact with the target object, wherein the tuning includes measuring,using a distance measurement sensor, a first distance between thedistance measurement sensor and an upper surface of the bending head,and a second distance between the distance measurement sensor and anupper surface of the stage for each zone, calculating a slope of thebending head based on the first distance, and calculating a slope of thestage based on the second distance; adjusting the slope of the bendinghead when the slope of the bending head is out of a tolerance range, andadjusting the slope of the stage when the slope of the stage is out of atolerance range; measuring a third distance that is a height differencebetween the upper surface of the bending head and the upper surface ofthe stage using the distance measurement sensor; and adjusting aposition of the bending head when the third distance is out of atolerance range.

The display device manufacturing apparatus according to an embodiment iscapable of improving reliability and display quality of a display devicemanufactured from a process target object by bending the process targetobject stably and accurately.

The display device manufacturing method according to an embodiment iscapable of improving reliability and display quality of a display devicemanufactured from a process target object by bending the process targetobject stably and accurately.

The effects of the inventive concepts are not limited to theaforementioned effects, and various other effects are included in thepresent specification.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects and features of the inventive concepts willbecome is more apparent by describing in detail exemplary embodimentsthereof with reference to the attached drawings, in which:

FIG. 1 is a plan view illustrating a display device according to anexemplary embodiment;

FIG. 2 is a schematic partial cross-sectional view illustrating adisplay device according to an exemplary embodiment;

FIG. 3 is a perspective view illustrating a display device-manufacturingapparatus according to an exemplary embodiment;

FIG. 4 is a schematic view illustrating a bending process using adisplay device-manufacturing apparatus according to an exemplaryembodiment;

FIG. 5 is a schematic view illustrating an operation of an upper sensoraccording to an exemplary embodiment;

FIG. 6 is a schematic view illustrating an operation of a side sensoraccording to an exemplary embodiment;

FIG. 7 is a schematic view illustrating a bending unit according to anexemplary embodiment;

FIG. 8 is a flowchart illustrating a method of inspecting and correctingpositions of a stage and a bending unit according to an exemplaryembodiment; and

FIGS. 9, 10, 11, and 12 are schematic views illustrating an inspectionand correction method of a stage and a bending unit according to anexemplary embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate exemplary embodiments of theinvention, and together with the description serve to explain theinventive concepts.

Detailed Description

In the following description, for the purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of various exemplary embodiments or implementations of theinvention. As used herein “embodiments” and “implementations” areinterchangeable words that are non-limiting examples of devices ormethods employing one or more of the inventive concepts disclosedherein. It is apparent, however, that various exemplary embodiments maybe practiced without these specific details or with one or moreequivalent arrangements. In other instances, well-known structures anddevices are illustrated in block diagram form in order to avoidunnecessarily obscuring various exemplary embodiments. Further, variousexemplary embodiments may be different, but do not have to be exclusive.For example, specific shapes, configurations, and characteristics of anexemplary embodiment may be used or implemented in another exemplaryembodiment without departing from the inventive concepts.

Unless otherwise specified, the illustrated exemplary embodiments are tobe understood as providing exemplary features of varying detail of someways in which the inventive concepts may be implemented in practice.Therefore, unless otherwise specified, the features, components,modules, layers, films, panels, regions, and/or aspects, etc.(hereinafter individually or collectively referred to as “elements”), ofthe various embodiments may be otherwise combined, separated,interchanged, and/or rearranged without departing from the inventiveconcepts.

The use of cross-hatching and/or shading in the accompanying drawings isgenerally provided to clarify boundaries between adjacent elements. Assuch, neither the presence nor the absence of cross-hatching or shadingconveys or indicates any preference or requirement for particularmaterials, material properties, dimensions, proportions, commonalitiesbetween illustrated elements, and/or any other characteristic,attribute, property, etc., of the elements, unless specified. Further,in the accompanying drawings, the size and relative sizes of elementsmay be exaggerated for clarity and/or descriptive purposes. When anexemplary embodiment may be implemented differently, a specific processorder may be performed differently from the described order. Forexample, two consecutively described processes may be performedsubstantially at the same time or performed in an order opposite to thedescribed order. Also, like reference numerals denote like elements.

The D1-axis, the D2-axis, and the D3-axis are not limited to three axesof a rectangular coordinate system, such as the x, y, and z-axes, andmay be interpreted in a broader sense. For example, the D1-axis, theD2-axis, and the D3-axis may be perpendicular to one another, or mayrepresent different directions that are not perpendicular to oneanother. For the purposes of this disclosure, “at least one of X, Y, andZ” and “at least one selected from the group consisting of X, Y, and Z”may be construed as X only, Y only, Z only, or any combination of two ormore of X, Y, and Z, such as, for instance, XYZ, XYY, YZ, and ZZ. Asused herein, the term “and/or” includes any and all combinations of oneor more of the associated listed items.

Although the terms “first,” “second,” etc. may be used herein todescribe various types of elements, these elements should not be limitedby these terms. These terms are used to distinguish one element fromanother element. Thus, a first element discussed below could be termed asecond element without departing from the teachings of the disclosure.

The terminology used herein is for the purpose of describing particularembodiments and is not intended to be limiting. As used herein, thesingular forms, “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. Moreover,the terms “comprises,” “comprising,” “includes,” and/or “including,”when used in this specification, specify the presence of statedfeatures, integers, steps, operations, elements, components, and/orgroups thereof, but do not preclude the presence or addition of one ormore other features, integers, steps, operations, elements, components,and/or groups thereof. It is also noted that, as used herein, the terms“substantially,” “about,” and other similar terms, are used as terms ofapproximation and not as terms of degree, and, as such, are utilized toaccount for inherent deviations in measured, calculated, and/or providedvalues that would be recognized by one of ordinary skill in the art.

Various exemplary embodiments are described herein with reference tosectional and/or exploded illustrations that are schematic illustrationsof idealized exemplary embodiments and/or intermediate structures. Assuch, variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. Thus, exemplary embodiments disclosed herein should notnecessarily be construed as limited to the particular illustrated shapesof regions but are to include deviations in shapes that result from, forinstance, manufacturing. In this manner, regions illustrated in thedrawings may be schematic in nature and the shapes of these regions maynot reflect actual shapes of regions of a device and, as such, are notnecessarily intended to be limiting.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure is a part. Terms,such as those defined in commonly used dictionaries, should beinterpreted as having a meaning that is consistent with their meaning inthe context of the relevant art and should not be interpreted in anidealized or overly formal sense, unless expressly so defined herein.

The present invention will now be described more fully hereinafter withreference to the accompanying drawings, in which preferred embodimentsof the invention are illustrated. This invention may, however, beembodied in different forms and should not be construed as limited tothe embodiments set forth herein. Rather, these embodiments are providedso that this disclosure will be thorough and complete, and will fillyconvey the scope of the invention to those skilled in the art.

It will also be understood that when a layer is referred to as being“on” another layer or substrate, it can be directly on the other layeror substrate, or intervening layers may also be present. In contrast,when an element is referred to as being “directly on” another element,there are no intervening elements present. To this end, the term“connected” may refer to physical, electrical, and/or fluid connection,with or without intervening elements.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the exemplary term “below” can encompass both anorientation of above and below. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

The same reference numbers indicate the same components throughout thespecification.

Hereinafter, exemplary embodiments will be described with reference tothe accompanying drawings.

FIG. 1 is a plan view illustrating a display device according to anexemplary embodiment. FIG. 2 is a schematic partial cross-sectional viewillustrating a display device according to an exemplary embodiment.

Referring to FIGS. 1 and 2 , a display device DD is a device configuredto display a moving image or a still image. The display device DD may beused as a display screen of various products such as televisions, laptopcomputers, monitors, billboards and the Internet of Things as well asportable electronic devices such as mobile phones, smart phones, tabletpersonal computers (tablet PCs), smart watches, watch phones, mobilecommunication terminals, electronic notebooks, electronic books,portable multimedia players (PMPs), navigation systems and ultra mobilePCs (UMPCs). Examples of the display device DD may include an organiclight emitting display device, a liquid crystal display device, a plasmadisplay device, a field emission display device, an electrophoreticdisplay device, an electrowetting display device, a quantum dot lightemitting display device, a micro LED display device, and the like.Hereinafter, an organic light emitting display device will be describedas an example of the display device, but the inventive concepts are notlimited thereto.

The display device DD may include a display panel 10. The display panel10 may include a flexible substrate including a flexible polymermaterial such as polyimide. Accordingly, the display panel 10 can bebent, folded or rolled.

The display panel 10 may include a main region MR and a bending regionBD connected to one side of the main region MR. The display panel 10 mayfurther include a sub-region SR which is connected to the bending regionBD and overlaps the main region MR in a thickness direction.

When a portion of the display panel 10 displaying a screen is defined asa display area DA and a portion of the display panel 10 not displaying ascreen is defined as a non-display area NDA, the display area DA of thedisplay panel 10 is disposed in the main region MR. The remainingportion other than the display area DA becomes the non-display area NDAof the display panel 10. In one embodiment, a peripheral edge portion ofthe display area DA in the main region MR, the entire bending region BDand the entire sub-region SR may be the non-display area NDA. However,the inventive concepts are not limited thereto, and the bending regionBD and/or the sub-region SR may also include the display area DA.

The main region MR may have a shape substantially similar to an outershape of the display device DD in plan view. The main region MR may be aflat region located on one plane. However, the inventive concepts arenot limited thereto, and at least one edge of the remaining edges exceptan edge (side) of the main region MR connected to the bending region BDmay be bent in a curved shape or bent in a vertical direction.

The display area DA of the display panel 10 may be disposed at thecenter of the main region MR. The display area DA may include aplurality of pixels. The display area DA may have a rectangular shape ora rectangular shape with rounded corners. However, the inventiveconcepts are not limited thereto, and the display area DA may havevarious shapes such as a square, other polygons, a circle, an ellipse orthe like.

If at least one of the edges other than the edge of the main region MRconnected to the bending region BD is curved or bent, the display areaDA may also be disposed on the corresponding edge. However, theinventive concepts are not limited thereto, and the non-display area NDAthat does not display a screen may be disposed on the curved or bentedge. Alternatively, both the display area DA and the non-display areaNDA may be disposed thereon.

The non-display area NDA may be located around the display area DA inthe main region MR. The non-display area NDA of the main region MR maybe placed in an area from the outer boundary of the display area DA tothe edge of the display panel 10. Signal lines or driving circuits maybe disposed in the non-display area NDA of the main region MR to apply asignal to the display area DA.

In the bending region BD, the display panel 10 may be bent with acurvature downward in a thickness direction, i.e., a direction oppositeto a display surface. The bending region BD may have a constant radiusof curvature. However, without being limited thereto, the bending regionBD may have a different radius of curvature for each section. Thesurface of the display panel 10 is reversed as the display panel 10 isbent in the bending region BD. In other words, one surface of thedisplay panel 10 facing upward may be changed to face outward throughthe bending region BD and then to face downward.

The sub-region SR extends from the bending region BD. The sub-region SRmay extend in a direction parallel to the main region MR from a pointwhere bending is completed. The sub-region SR may overlap the mainregion MR in the thickness direction of the display panel 10. Thesub-region SR may overlap the non-display area NDA of the edge of themain region MR and further overlap the display area DA of the mainregion MR.

The width of the sub-region SR may be the same as the width of thebending region BD, but is not limited thereto.

A driving chip 30 may be disposed on the sub-region SR of the displaypanel 10. The driving chip 30 may include an integrated circuitconfigured to drive the display panel 10. In one embodiment, theintegrated circuit may be, but is not limited to, a data drivingintegrated circuit that generates and provides a data signal. Thedriving chip 30 may be mounted on the display panel 10 in the sub-regionSR. The driving chip 30, which is mounted on one surface of the displaypanel 10 which is the same surface as the display surface, may bemounted on the surface of the display panel 10 facing downward in thethickness direction as the bending region BD is bent and reversed asdescribed above such that the upper surface of the driving chip 30 facesdownward.

The driving chip 30 may be attached onto the display panel 10 through ananisotropic conductive film or through ultrasonic bonding. The width ofthe driving chip 30 in a horizontal direction may be smaller than thatof the display panel 10 in a horizontal direction. The driving chip 30may be disposed in a central portion of the sub-region SR in ahorizontal direction. The left edge and the right edge of the drivingchip 30 may be separated from the left edge and the right edge of thesub-region SR, respectively.

A pad portion (not illustrated) may be provided at the end of thesub-region SR of the display panel 10, and a printed circuit board 20may be connected to the pad portion (not illustrated). The printedcircuit board 20 may be a flexible printed circuit board or film.

FIG. 3 is a perspective view illustrating a display device-manufacturingapparatus according to an exemplary embodiment. FIG. 4 is a schematicview illustrating a bending process using a display device-manufacturingapparatus according to an exemplary embodiment. FIG. 5 is a schematicview illustrating an operation of an upper sensor according to anexemplary embodiment. FIG. 6 is a schematic view illustrating anoperation of a side sensor according to an exemplary embodiment. FIG. 7is a schematic view illustrating a bending unit according to anexemplary embodiment.

In reference to FIGS. 3 to 7 , the display device manufacturingapparatus according to an exemplary embodiment may include a supportfixture 100, a stage 200, a bending unit 300, a guide member 400, acontroller 500, an upper sensor 600, and a side sensor 700.

A process target object 1 may be placed on the stage 200. The processtarget object 1 may include the display panel 10, printed circuit board20, and driving chip 30. The stage 200 may provide a space to place theprocessing target object 1. In detail, a display panel 10 may be placedon the stage 200. The stage 200 may have, but is not limited to, arectangular parallelopiped shape with a flat upper surface, acylindrical shape, or other polyprism shapes.

The stage 200 may include a suction member 210 configured to fix thedisplay panel 10 placed on the upper surface thereof. The display panel10 placed on the stage 200 may be fixed on the upper surface of thestage 200 by means of the suction member 210. For example, the suctionmember 210 may be connected to a vacuum module (not illustrated)arranged outside the stage 200 and include suction holes configured toproduce a negative pressure. However, the inventive concepts are notlimited thereto, and the suction member 210 may include an adhesionchuck or an electrostatic chuck. Although will be described later, aprocess configured to bend the process target object 1 with the bendingunit 300 may be carried out in the state where the display panel 10 isfixed on the stage 200. The stage 200 may be replaced depending on thekind of the display panel 10. For example, the stage 200 may be replaceddepending on the size, shape, and material of the display panel 10.

On the bottom part of the stage 200, a stage drive member 220 may bearranged to move the stage 200. The stage drive member 200 may have amechanical structure enabling the stage 200 to rotate. The stage drivemember 220 may also include a cylinder enabling the stage 200 to move inthe vertical direction. The stage drive member 220 may horizontally movein the first direction DR1 or the second direction DR2 or rotate on oneof an axis extending in the first direction DR1, an axis extending inthe second direction DR2, or an axis extending the third direction DR3due to the alignment or the nature of process. That is, the stage drivemember 220 may be provided with a transfer means configured to move thestage 200.

The stage 200 and the stage drive member 220 may be clamped together bya plurality of stage clamping members 230. In an exemplary embodiment,the stage drive member 220 may have clamping holes (not illustrated)each having a screw thread on the inner circumference thereof, and thestage 200 may have clamping pits (not illustrated) each having a screwthread on the inner circumference thereof. The stage clamping members230 may be, but are not limited to, bolts each having a screw thread onthe outer circumference thereof to be engaged with the clamping holes ofthe stage drive member 220 and the clamping pits of the stage 200. Thestage clamping members 230 may clamp the stage 200 and the stage drivemember 220 to substantially the same fastening degree (or withsubstantially the same fastening force) such that the stage 200 and thestage drive member 220 substantially remain in parallel. As describedabove, the stage 200 may be replaced depending on the kind of thedisplay panel 10 to which the bending process is applied, and theplurality of stage clamping members 230 may be removed and reinstalledwhenever the stage 200 is replaced. In this case, if the stage clampingmembers 230 are reinstalled to different fastening degrees (or withdifferent fastening forces), the parallelism of the stage drive memberand the replaced stage 200 may be lost.

The stage drive member 220 may be connected to the guide member 400 toslide the stage 200. The guide member 400 may be located below the stagedrive member 220. In an exemplary embodiment, the guide member 400 mayhave a shape extended in the first direction DR1. The stage 200 may beconnected to the stage drive member 220 so as to slide along the guidemember 400 in the first direction DR1. In addition, the stage drivemember 220 may include an air floating means to reduce sliding frictionof the stage 200. In this case, the stage 200 may move with less force.

The support fixture 100 may be arranged under the guide member 400. Thesupport fixture 100 may support the guide member 400 during the process.The guide member 400 may be mounted on the support fixture 100, thestage drive member 220 may be mounted on the guide member 400, and thestage 200 may be connected onto the stage drive member 220. The supportfixture 100 may provide a space to place the stage 220.

The bending unit 300 may be arranged outside the stage 200, e.g., at oneside in the first direction DR1. Although it is depicted in FIGS. 3 to 6that the bending unit 300 is separated from the support fixture 100 asto be described later, the inventive concepts are not limited thereto,and the banding unit 300 may be mounted on the support fixture 100.

The bending unit 300 may contact one surface of a printed circuit board20 at one side of the printed circuit board 20. That is, the printedcircuit board 20 may contact the bending unit 300 at one side and may beconnected to the display panel 10 at the other side. The bending unit300 is configured to bend the display panel 10. In other words, thebending unit 300 moves the printed circuit board 20 while the bendingunit 300 is connected to the printed circuit board 20 in order to bendthe display panel 10. The bending unit 300 may have, but is not limitedto, a bar shape extending in the first direction DR1.

The bending unit 300 may include a bending head 310, a vertical movementmember 320, and a bending drive member 330. The bending unit 300 may bedriven by the vertical movement member 320 and the bending drive member330.

The bending head 310 may directly contact and fix the printed circuitboard 20 during the bending process. The bending head 310 may include asuction member 311 that directly contacts the printed circuit board 20and a connection member 312 connected with the bending drive member 330.The suction member 311 may fix the printed circuit board 20 in a vacuumsuction manner or an adhesion manner without being limited thereto.

The vertical movement member 320 may move the bending unit 300 in adirection perpendicular to the upper surface of the bending head 310.The vertical movement member 320 may include a cylinder.

The bending drive member 330 may rotate the bending unit 300 andhorizontally move the bending unit 300 to carry out the bending process.Although not illustrated, the bending drive member 330 may rotate on anaxis extending in the second direction DR2. The bending drive member 330may also move in the first and third directions DR1 and DR3. As to bedescribed later, the bending head 310 may be connected to the bendingdrive member 330 to rotate and move along with the bending drive member330. Accordingly, the printed circuit board 20 sucked onto the bendinghead 310 may rotate and move, as the bending drive member rotates andmoves, to perform the bending process on the process target object 1.

The connection member 312 and the bending drive member 330 may beconnected by a plurality of bending-clamping members 340. In anexemplary embodiment, the connection member 312 may have bendingconnection holes 312 h each having a screw thread on the innercircumference thereof, and the bending drive member 330 may have bendingconnection pits 330 h each having a screw thread on the innercircumference thereof. The bending-clamping members 340 may be, but arenot limited to, bolts each having a screw thread on the outercircumference thereof to be engaged with the bending connection holes312 h of the connection member 312 and the bending connection pits 330 hof the bending drive member 330. The bending-clamping members 340 mayclamp the connection member 312 of the bending head 310 and the bendingdrive member 330 to substantially the same fastening degree (or withsubstantially the same fastening force) such that the bending drivemember 330 and the connection member 312 substantially remain inparallel. As described above, the bending header 310 may be replaceddepending on the kind of the printed circuit board 200 to which thebending process is applied, which includes removal and reinstallation ofthe plurality of bending-clamping members 340. In this case, if thebending-clamping members 340 are reinstalled to different fasteningdegrees (or with different fastening forces), the parallelism of theconnection member 312 and the replaced bending drive member 330 may belost.

Although it is depicted that the bending unit 300 is arranged under thebottom part of the printed circuit board 20 in the drawings, theinventive concepts are not limited thereto, and the bending unit 300 maybe arranged on the upper part of the printed circuit board 20.

Although not illustrated, the bending unit 300 may further include abending controller (not illustrated). The operation of the bending unit300 may be controlled by the bending controller (not illustrated). Thebending controller (not illustrated) may include a measurement unit (notillustrated), a memory unit (not illustrated), a signal unit (notillustrated), and an operation unit (not illustrated).

The memory unit (not illustrated) may store a reference course and amovement course of the bending unit 300 that is measured by themeasurement unit (not illustrated). The signal unit (not illustrated)may produce a start signal and an end signal to the measurement unit(not illustrated). The measurement unit (not illustrated) may startmeasurement on the movement course of the bending unit 300 upon receiptof the start signal from the signal unit (not illustrated) and end themeasurement upon receipt of the end signal. The operation unit (notillustrated) may compare the movement course of the bending unit 300that was measured by the measurement unit (not illustrated) with thereference course or compare two or more movement courses of the bendingunit 300 that were measured by the measurement unit (not illustrated).

The bending controller (not illustrated) may control the bending drivemember 330 to drive the bending unit 300 based on a result of thecomparison carried out by the operation unit (not illustrated). That is,it may be possible to correct the movement course of the bending unit200 based on a result of the comparison carried out by the operationunit (not illustrated).

The display device manufacturing apparatus according to an exemplaryembodiment may include the controller 500. The controller 500 mayreceive signals from the upper sensor 600 and the side sensor 700 to bedescribed later and produce a correction signal to the stage drivemember 220 and the vertical movement member 320. That is, the controller500 may adjust the position of the vertical movement member 430 inrelation to the bending header 310 and the position of the stage drivemember 220 in relation to the stage 200.

The upper sensor 600 may be located at one side of the stage 200 and thebending unit 300 in the third direction DR3. The upper sensor 600 may bea laser sensor including a light transmission member 610 configured toemit a laser beam LB and a light reception member 620 configured toreceive the laser beam LB. The upper sensor 600 may be a distancemeasurement sensor. The upper sensor 600 may measure the time taken forthe laser beam LB transmitted by the light transmission member 610 toarrive at the light reception member 620 after being reflected on adistance measurement target object to determine the distance from theobject.

The upper sensor 600 may move in the first and second directions DR1 andDR2. Accordingly, the upper sensor 600 may scan the upper surface of thestage 200 and the bending unit 300 to measure the distance from theupper sensor 600 to the stage 200 and the distance from the upper sensor600 to the bending unit 300.

Although not illustrated, the upper sensor 600 may further include anupper sensor operation unit (not illustrated) and an upper sensordisplay unit (not illustrated). It may also be possible to calculate adegree of slope of a surface of the distance measurement target based onthe distance value measured by scanning per zone by means of the uppersensor operation unit (not v). The calculated measurement value may bedisplayed on the upper sensor display unit (not illustrated).

In an exemplary embodiment, the degree of slope of the distancemeasurement target may be derived from the slope calculated by the uppersensor operation unit (not illustrated) based on a maximum value and aminimum value among the distance values measured in the correspondingzone and a horizontal distance between a point having the maximum valueand a point having the minimum value. In another embodiment, the degreeof slope of the distance measurement target may be derived from astandard deviation calculated by the upper sensor operation unit (notillustrated) based on the data of the distance values measured in thecorresponding zone.

It may be possible to measure a first height difference h1 as the heightdifference between the upper surface of the stage 200 and the uppersurface of the bending unit 300 by using the upper sensor 600. The firstheight difference h1 may be measured in the state where the uppersurface of the stage 20 and the upper surface of the bending unit arealigned in parallel. The first height difference h1 may be derived froma distance from the upper sensor 600 to the upper surface of the stage200 and a distance from the upper sensor 600 to the upper surface of thebending unit 300. Although the first height difference h1 may be mostlyequal to the thickness of the printed circuit board 20 in an exemplaryembodiment, the inventive concepts are not limited thereto.

The upper sensor 600 may measure the distance between the upper sensor600 and the upper surface of the bending head 310 and the distancebetween the upper sensor 600 and the upper surface of the stage 200 andsend a measurement result to the controller 500, which may derive thedistance between the upper surface of the bending head 310 and the uppersurface of the stage 200 based on the respective distances and determinea position adjustment amount of the vertical movement member 320 in thevertical direction based on the derived distance.

The side sensor 700 may be located at one side of the stage 200 in thesecond direction DR2. The side sensor 700 may include a camera module(not illustrated).

In an exemplary embodiment, the side sensor 700 may move in the firstdirection DR1. The side sensor 700 may be adjusted in height or remain,if there is no manipulation, at the corresponding height. The sidesensor 700 may sense the stage 200 along a reference line VL. Thereference line VL may be a virtual line extending in a direction towhich the side sensor 700 is oriented. In an exemplary embodiment, thereference line VL of the side sensor 700 may be level with the uppersurface of the stage 200. The side sensor 700 may sense a change of theheight of the upper surface of the stage 200 when the stage 200 isreplaced. For example, the upper surface of the stage 200 may be set tobe level with the reference line VL of the side sensor 700. In the casewhere the upper surface of the stage 200 is out of level with thereference line VL, the side sensor 700 may generate a signal to thecontroller 500 in order for the controller 500 to control the stagedrive member 220 such that the upper surface of the stage 200 ispositioned level with the reference line VL. That is, because the heightof the side sensor 700 remains constant even when the stage 200 isreplaced, it may be possible to minimize a height variation of the stage200 by setting the height of the upper surface of the replaced stage 200to be level with the reference line VL of the side sensor 700.

The display device manufacturing apparatus according to an exemplaryembodiment is capable of identifying degrees of slopes of the stage 200and the bending unit 300. It may also be possible to measure the heightof the stage 200 and the height of the bending unit 300 based on theheight of the stage 200 for automatic correction. This may make itpossible for the process target object 1 to be accurately placed acrossthe stage 200 and the bending unit 300 and stably bent by the bendingunit 300, which leads to improvement of the reliability and displayquality of the display device DD manufactured from the process targetobject 1.

Hereinafter, a description is made of a method of manufacturing adisplay device according to an exemplary embodiment. That is, theoperation of the apparatus configured to manufacture a display device isdescribed.

FIG. 8 is a flowchart illustrating a method of inspecting and correctingpositions of a stage and a bending unit according to an exemplaryembodiment. FIGS. 9 to 12 are schematic views illustrating an inspectionand correction method of a stage and a bending unit according to anexemplary embodiment.

The display device manufacturing method according to an exemplaryembodiment may include inspecting and correcting positions of the stage200 and the bending head 310, arranging the process target object 1 onthe stage 200, and bending the process target object 1 that is in thestate of contacting the bending head 310.

Hereinafter, a description is made of the method of inspecting andcorrecting the positions of the stage 200 and the bending head 310 withreference to FIGS. 8 to 12 .

In reference to FIG. 8 , the method of inspecting and correctingpositions of the stage 200 and the bending head 310 according to anembodiment may include measuring slopes of the stage 200 and the bendinghead 310 with the upper sensor at operation S100, determining atoperation S200 whether the slopes of the stage and the bending head areeach out of a predetermined tolerance range, correcting slopes atoperation S210, measuring a height of the stage with the side sensor atoperation S300, determining at operation S400 whether the height of thestage is out of a tolerance range, correcting the height at operationS410, measuring a height difference between the stage and the bendinghead with the upper sensor at operation S500, determining at operationS600 whether the height difference between the stage and the bendinghead is out of a tolerance range, and correcting the height differenceat operation S610.

Correcting the slopes of the stage and the bending head at operationS210, correcting the height of the stage at operation S410, andcorrecting the height difference between the stage and the bending headat operation S610 may be carried out in the cases where the slopes, theheight, and the height difference are determined out of thecorresponding tolerance ranges respectively at operations S200, S400,and S600.

In reference to FIGS. 8, 9, and 10 , the method of inspecting andcorrecting the positions of the stage 200 and the bending head 310according to an embodiment may be carried out by preferentiallymeasuring the slopes of the stage 200 and the bending head 310. Theslope measurement may be carried out first on the stage 200 and then thebending head 310, but not limited thereto, and may be carried out firston the bending head 310.

Measuring the slopes of the stage 200 and the bending head 310 atoperation S100 may be carried out on the upper surfaces of the stage 200and the bending head 310 via laser scanning with the upper sensor 600.As described above, the upper sensor 600 may include the lighttransmission member 610 configured to emit the laser beam LB and thelight reception member 620 configured to receive the laser beam LB. Theupper sensor 600 may measure the time taken for the laser beam LBtransmitted by the light transmission member 610 to arrive at the lightreception member 620 after being reflected on the upper surfaces of thestage 200 and the bending head 310 to determine the distance from theobject. The zone being substantially scanned by the laser beam LB on thebending head 310 may be the suction member 311.

The slope of the stage 200 may be derived based on the maximum value andminimum value among the per-zone distance values of the upper surface ofthe stage 200 that are measured from the upper sensor 600 and thehorizontal distance between the points having the maximum and minimvalues. For example, the stage 200 may be sloped such that one endthereof in the second direction DR2 is down and the other end thereof inthe second direction DR2 is up. The distance from the upper sensor 600to the one end of the stage 200, which is measured in the seconddirection DR2, may be referred to as first distance d1, and the distancefrom the upper sensor 600 to the other end may be referred to as seconddistance d2; the second distance d2 may be greater than the firstdistance d1. The slope of the stage 200 may be derived based on thefirst distance d1, the second distance d2, and the distance between theone and the other ends of the stage 200.

The slope of the bending head 310 may be derived based on the maximumand minimum values among the per-zone distance values of the uppersurface of the bending head 310 that are measured from the upper sensor600 and the horizontal distance between the points having the maximumand minimum values. Because the laser beam LB emitted from upper sensor600 substantially scans the suction member 311 of the bending head 310,the slope of the bending head 310 may be derived based on the maximumand minimum values among the per-zone distance values of the uppersurface of the suction member 311 that are measured from the uppersensor 600 and the horizontal distance between the points having themaximum and minimum values. For example, the suction member 311 may besloped such that one end is up and the other end is down in the firstdirection DR1. The distance from the upper sensor 600 to the other endof the suction member 311 in the first direction DR1 may be referred toas third distance d3, and the distance from the upper sensor 600 to oneend of the suction member 311 in the first direction DR1 may be referredto as fourth distance d4; the fourth distance d4 may be less than thethird distance d3. The slope of the bending head 310 may be derivedbased on the third distance d3, the second distance d3, and the distancebetween the one and the other ends of the suction member 311.

However, the inventive concepts are not limited thereto, the slope ofthe bending head 310 may be derived based on a standard deviationcalculated based on the data of the distance values measured in the zonescanned with the laser beam LB.

Measuring the slopes of the stage 200 and the bending head 310 with theupper sensor 600 at operation S100 may be followed by determining atoperation S200 whether the slopes of the stage and the bending head areeach out of a predetermined tolerance range and correcting the slope atoperation S210. Although it is preferable that the stage 200 and thebending head 310 are level without being sloped, i.e., in the state ofhaving the slope of 0, the bending process may be carried out if theslope is in the tolerance range. The tolerance range of the slopes ofthe stage 200 and the bending head 310 may vary depending on the processtarget object 1 to be bent.

As described above, correcting the slopes of the stage 200 and thebending head 310 at operation S210 may be carried out in the case wherethe slopes of the stage 200 and the bending head 310 that have beenderived previously are out of the tolerance range. Correcting the slopeof the stage 200 may include adjusting the fastening degree (orfastening force) of each of the plurality of stage clamping members 230.Correcting the slope of the bending head 310 may also include, but isnot limited to, adjusting the fastening degree (or fastening force) ofeach of the plurality of bending-clamping members 340. The upper surfaceof the slope-corrected stage 200 and bending head 310 may besubstantially level.

However, in the case where the slopes of the stage 200 and the bendinghead 310 are in the tolerance range, measuring the height of the stagewith the side sensor at operation S300 may be carried out as the nextoperation.

In reference to FIGS. 8 and 11 , the side sensor 700 fixed in height ata side of the stage 200 may sense a change of the height of the uppersurface of the stage 200. In an exemplary embodiment, if the height ofthe stage 200 is changed, it may be possible to measure a heightdifference a1 between the reference line VL and the upper surface of thestage 200.

Measuring the height of the stage 200 with the side sensor 700 atoperation S300 may be followed by determining at operation S400 whetherthe height of the stage is out of the tolerance range and correcting theheight at operation S410. In an exemplary embodiment, the bendingprocess may be carried out if the height of the stage 200 measured fromthe reference line VL is in the predetermined tolerance range. Thetolerance range of the height of the stage 200 may vary depending on theprocess target object 1.

As described above, correcting the height of the stage 200 at operationS410 may be carried out in the case where the height of the stage 200measured from the reference line VL is out of the tolerance range.Correcting the height of the stage 200 may be carried out in such a waythat the controller 500 controls the stage drive member 220 to drive thestage 200 to move in the vertical direction. For example, in the casewhere the upper surface of the stage 200 is out of level with thereference line VL, the side sensor 700 may generate a signal to thecontroller 500 in order for the controller 500 to control the stagedrive member 220 to drive the stage 200 to move the upper surface of thestage 200 as much as the height difference a1 in the vertical directionso as to be level with the reference line VL. Although the height of thestage 200 may be automatically measured and corrected under the controlof the controller 500, the inventive concepts are not limited thereto.

However, in the case where the height of the stage 200 is in thetolerance range, measuring the height difference between the stage andthe bending head with the upper sensor at operation S500 may be carriedout.

In reference to FIGS. 8 to 12 , it may be possible to measure the heightdifference between the upper surfaces of the stage 200 and the bendinghead 310 with the upper sensor 600. As described above, the upper sensor600 may be a distance measurement sensor that is capable of measuring adistance from the upper sensor 600 to the upper surface of the stage 200and a distance from the upper sensor 600 to the upper surface of thebending head 310, and the height difference between the upper surfacesof the stage 200 and the bending head 310 may be derived from the twodistances.

As described above, correcting the height difference between the stage200 and the bending head 310 at operation S610 may be carried out in thecase where the previously measured height difference between the stage200 and the bending head 310 is out of the tolerance range. Correctingthe height difference between the stage 200 and the bending head 310 maybe carried out in such a way that the controller 500 controls thevertical movement member 320 of the bending unit 300 to move the bendingunit 300 in the vertical direction.

In an exemplary embodiment, the height difference between the uppersurfaces of the stage 200 as the reference and the bending head 310 maybe referred to as first height difference h1. If at least one of thestage 200 and the bending unit 300 changes in height, the heightdifference between the upper surfaces of the stage 200 and the bendinghead 310 may be changed to a second height difference h2. In this case,the upper sensor 600 may generate a signal to the controller 500 inorder for the controller 500 to control the vertical movement member 320of the bending unit 300 to move such that the height difference betweenthe upper surfaces of the stage 200 and the bending head 310 iscorrected to be the first height difference h1. Although measuring andcorrecting the height difference between the stage 200 and the bendinghead 310 may be automatically carried out under the control of thecontroller 500, the inventive concepts are not limited thereto.

However, in the case where the height difference between the stage 200and the bending head 310 is in the tolerance range, arranging theprocess target object 1 on the stage 200 and bending the process targetobject 1 in the state of contacting the bending head 310 may be carriedout as subsequent operations. The description of the process to bend theprocess target object 1 has been made with reference to FIGS. 3 to 7 andis omitted hereinafter.

According to an embodiment, the display device manufacturing method maybe capable of identifying the degree of slope of each of the stage 200and the bending unit 300. It may also be possible to measure the heightof the stage 200 and the height of the bending unit 300 in relation tothe height of the stage 200 and correct the height of the bending unit300. This makes it possible for the process target object 1 to beaccurately placed across the stage 200 and the bending unit 300 andstably bent by the bending unit 300, which leads to improvement of thereliability and display quality of the display device DD manufacturedfrom the process target object 1.

In concluding the detailed description, those skilled in the art willappreciate that many variations and modifications can be made to thepreferred embodiments without substantially departing from theprinciples of the present invention. Therefore, the disclosed preferredembodiments of the invention are used in a generic and descriptive senseonly and not for purposes of limitation.

What is claimed is:
 1. An apparatus configured to manufacture a displaydevice, comprising: a stage configured to place a process target objecton an upper surface thereof; a bending head in contact with the processtarget object to bend the process target object; a distance measurementsensor installed above the stage to be movable in a horizontaldirection; a cylinder configured to adjust a vertical position of thebending head; and a controller configured to control the positionadjustment of the cylinder with respect to the bending head, wherein thedistance measurement sensor measures a first distance between thedistance measurement sensor and an upper surface of the bending head anda second distance between the distance measurement sensor and the uppersurface of the stage, respectively, and transmits the measured distancesto the controller, and the controller derives a third distance betweenthe upper surface of the bending head and the upper surface of the stagebased on the first distance and the second distance, and determines aposition adjustment amount of the cylinder in a vertical direction basedon the third distance.
 2. The apparatus of claim 1, wherein the distancemeasurement sensor includes a light transmission member configured toemit a laser beam and a light reception member configured to receive thelaser beam.
 3. The apparatus of claim 2, wherein the distancemeasurement sensor calculates a distance by measuring a time taken forthe laser beam emitted from the light transmission member to arrive atthe light reception member.
 4. The apparatus of claim 1, furthercomprising: a height measurement sensor disposed outside the stage,wherein the height measurement sensor measures a height differencebetween the height measurement sensor and the upper surface of thestage.
 5. The apparatus of claim 4, wherein the height measurementsensor includes a camera module.
 6. The apparatus of claim 1, furthercomprising: a first horizontal adjustment member configured to adjusthorizontality of the bending head; and a second horizontal adjustmentmember configured to adjust horizontality of the stage.
 7. The apparatusof claim 1, wherein the upper surface of the stage and the upper surfaceof the bending head are in parallel with each other.
 8. The apparatus ofclaim 1, further comprising: a stage drive member to which the stage isfastened; and a guide member having a shape extending in one directionand guiding movement of the stage drive member.
 9. The apparatus ofclaim 8, wherein the stage drive member includes a second cylinderconfigured to adjust a vertical position of the stage.
 10. The apparatusof claim 1, wherein the bending head includes a first suction member.11. The apparatus of claim 10, wherein the first suction member includesa plurality of suction holes configured to provide a negative pressure.12. The apparatus of claim 11, wherein the stage includes a secondsuction member.
 13. The apparatus of claim 12, wherein the processtarget object includes a first element and a second element partiallycontacting the first element, and the first element is sucked onto thefirst suction member, and the second element is sucked onto the secondsuction member.